Ontologies are formalizations of knowledge that are built utilizing the principles of abstraction and modelling. An ontology models (like a formal specification of a program), the concepts and relationships that can formally exist for an agent or a collection of agents pertaining to some subject matter of interest to a particular community (e.g., business operators, medical practitioners, educators, technologists). At its elemental level, an ontology can be equated with taxonomic hierarchies of classes, class definitions, and the subsumption relation (superclass-subclass decompositions), along with the interrelationships between such object classes